One thread running through many criminal exoneration cases in Texas involves prosecutors who failed their legal and moral duty to justice and fair play.

Too many of them appear to have been more interested in winning a conviction than airing the whole truth, even at the expense of someone’s liberties.

Lawmakers need to unravel these tangled messes, then find ways to build safeguards against willful or sloppy miscarriage of justice in a district attorney’s office.

Defendants have a constitutional right to evidence held by the state when that information could be favorable to their defense.

But review this litany, just from the past few weeks, of cases involving improperly concealed evidence: Dale Lincoln Duke walked out of the Dallas County courthouse after 14 years, a Tarrant County woman cut a deal to get off death row, and Michael Morton was freed in Williamson County after nearly 25 years on a trumped-up murder charge.

Over the summer, Anthony Graves was awarded $1.4 million as compensation for a bogus murder conviction and 18 years in prison, including death row. His fate would have been different had his trial lawyers known what the district attorney was hiding.

A DA’s office can help immunize itself against charges of withholding evidence through an “open file” policy, in which the defense may see the material compiled by investigators. Most Texas DAs have adopted such policies over the years, but the practices are uneven, with some counties more restrictive than others.

The Timothy Cole Advisory Panel on Wrongful Convictions, a broad base of criminal justice experts formed by the Legislature, has recommended uniform, reciprocal discovery procedures whereby defense and prosecuting attorneys can access one another’s files.

Many other states operate that way: cards on the table, forget the cat-and-mouse game. Texas’ embarrassment of exonerations should be a strong motivation to fall in line.

Improved training is another step the state should take. There now is no mandatory course or refresher that the state requires of prosecutors to ensure that everyone is clear on obligations to share evidence. Considering the authority that prosecutors wield, there is compelling public interest in making sure they understand their roles in ensuring constitutional rights.

Finally, though a prosecutor can be criminally charged for misusing his position, an individual who is railroaded by a crooked DA has no access to state courts to pursue civil claims.

Legislation was filed this year to provide that access and limit a prosecutor’s immunity, but the bill went nowhere, with no debate. Lawmakers should take another look, give the matter their full attention and hear pros and cons.

The vast majority of prosecutors are honorable public servants and should not have to look over their shoulders in fear of nuisance suits. That could drive them out of the profession.

But there are outliers in any occupation, and they should not be immune from accountability.

Recent cases with charges of prosecutorial misconduct

Dale Lincoln Duke, 60, was released in Dallas County on Nov. 4 after 14 years in prison, his conviction on child abuse charges declared “unjust” by a judge. The DA’s office said a prosecutor withheld evidence that the child’s grandmother thought the girl was lying.

Chelsea Richardson, 27, won an appeal Nov. 1 that got her off death row and will mean life in prison. She was convicted of masterminding the murder of her boyfriend’s parents in Mansfield, but notes withheld from the defense show a different defendant may have played the key role.

Michael Morton, 57, was freed in Williamson County on Oct. 4 after nearly 25 years in prison for the murder of his wife. DNA tests implicated another man, who was arrested last week. Defense lawyers charge that the DA withheld information that Morton’s son saw a “monster” do the killing. Now a judge, the district attorney is under investigation by the State Bar of Texas.

Anthony Graves collected $1.4 million in compensation July 1 for a bogus conviction in the murder of six people and 18 years in prison, including death row. Graves, 45, was freed in October 2010. Prosecutors proclaimed him innocent and said the former Burleson County DA manipulated witnesses to gain a conviction.

To post a comment, log into your chosen social network and then add your comment below. Your comments are subject to our Terms of Service and the privacy policy and terms of service of your social network. If you do not want to comment with a social network, please consider writing a letter to the editor.